Static magnetic components such as inductors and transformers have traditionally been constructed using windings of ordinary conducting wire having a circular cross section. This arrangement normally produces a structure having dimensions that are substantial in all three dimensions as contrasted to other components such as capacitors and semiconductor devices which frequently have a small third dimension (height). Manufacture of these traditional structures involves winding the wire around a core or bobbin structur, a process that often involves considerable amounts of expensive hand labor. Furthermore high power applications often require a magnetic component having a bulky core and large wire sizes for the windings.
New operational requirements with respect to circuit size and power density and increasing necessity to reduce circuit manufacturing costs have made the traditional static magnetic component very unattractive as circuit components. Newly designed circuits, for example, need low profiles to accommodate the decreasing space permitted to power circuits. Attaining these objectives has required the redesign of magnetic components to achieve a low profile and a low cost component assembly.
An example of a presently available magnetic component with a low profile and low assembly costs is disclosed in U.S. Pat. No. 4,583,068. In this arrangement a ribbon winding is used for inductor applications and a winding with a channel shaped cross section is used as a first winding for transformer applications with the second winding being of conventional wire placed within the channel shaped cross section of the first winding. In this arrangement the first winding is limited to one turn. An arrangement using two juxtaposed windings, each of which has a channel shaped cross section, is shown in U.S. Pat. No. 4,616,205. This arrangement allows a two turn first winding.
These arrangements while a considerable improvement over traditional construction of magnetic components still fail to meet the performance and cost objectives of contemporary circuit designs.